Other than this it's the same steps as sthone outlined. So you avoid the whole business of having to leave your computer plugged in. Of course, like I said previously you still have to be watching the printer closely otherwise you'd miss the 60 s pause. I don't see why you couldn't make it longer if you wanted though.

WooHoo! This totally works!......Check out the little Stop Sign bookmarks I worked up for the nephews' Christmas stockings.......

Nyah! Nyah! Nyah! Nyah!I printed two colors with one nozzle......I printed two colors with one nozzle......

One thing i was noticing as I was trying to make these work....you definitely need to make sure you have a solid layer underneath the layer that you start the color change on, and another thing that puzzled me - when the switched-out color started printing, it didn't extrude for a while (few inches) before it kicked in. Not that there was any red coming out either - nothing was extruding.

Tried adding a little E2 code to squirt out a couple of mm, it just spit that out and then stopped extruding for a couple of inches.Curioser and curioser!

Anyway, it's a funtastic development Steve - many thanks for posting the instructions!

Jules wrote:One thing i was noticing as I was trying to make these work....you definitely need to make sure you have a solid layer underneath the layer that you start the color change on, and another thing that puzzled me - when the switched-out color started printing, it didn't extrude for a while (few inches) before it kicked in. Not that there was any red coming out either - nothing was extruding.

I was doing some duel colors the other day (following my own tutorial because I suffer from CRS) and I noticed some weird stuff too. At first I thought my instructions were flawed because after changing the color and hitting the resume print button the printer was retracting the filament before starting again. The weird part is it didn't always do this, (I tried it a few times) sometimes it retracted it and and sometimes it didn't. I was running the same g code each time so I'm not really sure whats going on as I couldn't figure it out.

I still have to play around with it but if anyone has any ideas on this I'm all ears.

sthone wrote:...after changing the color and hitting the resume print button the printer was retracting the filament before starting again.

Yeah, that was exactly what it was like....it took it a while to get the filament back down into place.

Wonder what the heck is causing that? i looked at the code, line by line at that spot, and didn't see anything that looked like a retraction command. (Negative number on Feedrate or Extrusion?)It's a gremlin......

Some slicers (S3D) specify extrusions in absolute coordinates. I think the firmware is tracking whatever extrusions you are doing while it is paused and reversing it when you unpause. I think what you want to do is keep it in relative positioning before the pause, then set it back to absolute positioning after the pause. I haven't tried or looked into it, but it sounds plausible.

Hmmmmn - that might explain it all right - I extruded the living daylights out of it to clear the original color before starting back up again.So then, we need one more line of code inserted - switching back to absolute positioning after the pause command? Before the Pause command?

Will experiment.

Update:Well, the only thing I found that works is to retract the same amount as you plan to extrude.....

If you are changing the filament - retract 300 first, change the spool, then extrude 300 to clear the nozzle before you resume.

I tried every combination of M82 and M83 I could think of, before and after the pause, and sometimes they caused serious over-extrusion, so i'm likely putting it in the wrong place or those are just the wrong codes to use.

I guess that doesn't work. Not really sure how pausing is supposed to restart your print correctly if you've done a bunch of retractions/extrusions that don't cancel each other out. I've done some searching, and nobody seems to really thought this through or at least hasn't written it down. Your method of retracting just how much you want to extrude will work. You're on the cutting edge of research!

You can save yourself some time spinning back the retraction by going to relative mode and using G92 to set a negative extruder position without actually doing the retraction, I think: